WASHINGTON — The internal watchdog at the Department of Veterans Affairs has uncovered widespread errors in how the agency awards benefits to some of its most vulnerable patients: those diagnosed with the devastating neurological disease amyotrophic lateral sclerosis.

VA Inspector General Michael Missal, in a review released Tuesday, found that dozens of veterans suffering from ALS were deprived of financial support because staff mishandled their benefits claims.

Officials with the inspector general's office are concerned that the Veterans Benefits Administration, under pressure from Congress and veterans service organizations to reduce an enormous backlog of compensation claims and appeals, may be cutting corners.

Of 960 claims that were examined by Missal's office, 430 contained errors. Of those, 230 claimants were awarded the wrong benefits, the inspector general's report says. Most received no money or were underpaid. In other cases, officials could not determine whether the benefits VA paid were too low or too high.

Officials estimated that if the errors continue at the same rate over the next five years, VA will fail to pay $7.5 million in benefits to ALS patients and award an additional $6.5 million in erroneous payments.

"ALS is a devastating, aggressive disease," Missal told The Washington Post. "Accordingly, VA needs to ensure that claims reviewers are proficient and trained to properly and accurately assure that veterans are getting the full range of benefits to which they are entitled."

ALS, a rapidly progressive neurological disease that most often leads to death within three to five years from the onset of symptoms, afflicts at least 2,000 veterans a year. Studies show that military serviceputs veterans at up to twice the risk of contracting the disease, although scientists have not determined why that link exists.

Veterans diagnosed with ALS, also known as Lou Gehrig's disease, have been entitled since 2008 to automatic, service-connected benefits. Compensation ranges from $36,000 to $100,000 annually, depending on marital and family status, and related needs as the disease progresses.

The inspector general faulted poor training for the staff, comprising mostly low-level employees, tasked with reviewing the claims.

Employees who improperly denied claims failed to accurately evaluate the disease's many medical complications, and in dozens of cases they did not inform veterans or their caregivers that they were eligible for additional compensation to assist with related needs such as transportation, dressing and feeding, and specialized housing, investigators found.

Paul Lawrence, VA's undersecretary for benefits, agreed with the report's recommendation that his office create specialized training for reviewers handling ALS claims and inform the staff that they must tell veterans they are entitled to additional benefits for related needs.

A spokesman for VA, Curt Cashour, said that evaluating the disease's severity is "complex work that requires a detailed assessment of a veteran's medical history." The agency is committed, he added, "to improving its ALS claims-processing efforts so veterans receive the maximum benefits to which they are entitled."

ALS claims are among the most complex in VA's benefits system, in part because the disease progresses quickly with varied symptoms. The onset of symptoms — which can include twitching, cramping, muscle stiffness or weakness and slurred speech — may be so subtle that changes are overlooked.

VA employees are supposed to tell veterans about their right to extra compensation. But they did not, based on a narrow interpretation of a legal case, the inspector general's report says.

"Without information about [additional compensation], veterans with ALS may not know about and understand the benefits available to them and may mistakenly believe there are no additional benefits available," the report said.